Hybrid footwear liner

ABSTRACT

A flexible boot liner ( 100 ) having a flexible upper ( 101 ) and a semi-rigid sole ( 140 ) that provides durability, walkability, and a dimensionally stable fit within a boot ( 90 ). The sole includes a lasting board ( 160 ) that is fixedly attached to the upper and a nonskid outsole ( 142 ). Secondary cushioning devices such as an air cell ( 144 ) may also be incorporated into the sole. The upper is of hybrid construction including a relatively flexible bottom portion ( 120 ) thermoformed from an ethylene vinyl acetate foam that covers the foot and the malleoli of the user, and a semi-rigid upper portion ( 110 ) that wraps about the lower leg of the user. A strap assembly ( 150 ) is provided to secure the liner about the foot of the user.

FIELD OF THE INVENTION

[0001] The present invention relates generally to boot liners and, more particularly, to boot liners for high performance, sports related boots.

BACKGROUND OF THE INVENTION

[0002] High performance footwear—typically boots—are used in many sporting activities such as skiing, snowboarding, skating, hiking, and the like. Such high performance footwear must satisfy a number of competing demands. For example, snowboard boots must be rugged enough to reliably withstand the rigors of high-intensity snowboarding and the wet and freezing environmental conditions. The snowboard boot is firmly attached to the snowboard with a binding. However, for the user to achieve optimal performance, the user's foot and boot must be tightly coupled—that is, there should be minimal slop or play between the user's foot and the boot. Finally, the snowboard boot or other high performance footwear must provide a high level of comfort, including protection from the elements, for extended, often grueling, usage.

[0003] In order to meet these different requirements, very often such boots include a relatively soft, flexible liner that is disposed within the boot, between the boot and the user's foot. The liner may be removable from the boot or permanently attached to the boot. A liner provides many benefits. For example, the liner generally conforms better to the shape of the user's foot, providing a more exact fit between the user and the boot. The liner also helps to keep the user's foot warm, provides padding to the user, absorbs accumulated perspiration and other moisture, and provides a comfortable, snug fit between the user's foot and ankle, and the boot. The liner may provide shock absorption to the user's foot, and may provide additional support, particularly to the user's ankle. Removable liners have the additional advantage of being easily cleaned and replaced, as needed. A soft liner, however, may result in a poorer coupling between the user's foot and the boot, due to the liner being able to move somewhat within the boot.

[0004] Prior art boot liners may be simply sock-type liners, wherein the liner is generally L-shaped and tubular, with sufficient elasticity and flexibility to receive the user's foot. A longitudinal vamp or slit and tongue may be provided in the liner to facilitate putting on the liner and boot. The liner may also include a lacing system for tightening the liner about the user's leg and ankle. The liner must be sufficiently flexible to be inserted into the boot and be comfortable to the user, preferably without interfering with the flexibility of the boot. Ethylene vinyl acetate (EVA) has the desirable characteristics of pliability and compressibility, for cushioning and comfort, while also being relatively rugged and lightweight. EVA can be thermoformed to a three-dimensional shape that more closely conforms to the shape of the user's foot. However, it has been found that, over time, a liner made from EVA will pack outwardly away from the user's foot at the bottom of the liner, from wear and flexing over a relatively short time. Such packing out may result in a degradation in the quality of the fit between the liner and the boot, reduced comfort to the user, and frequent discarding and replacement of the liner.

[0005] In addition, the pliability and flexibility of EVA, while providing comfort and cushioning, may not provide a sufficiently rigidity or support to create a responsive fit, particularly about the ankle of the user. In many sports, such as snowboarding and skiing, it is desirable to provide sturdy and stable support to the user's ankle to permit the user to quickly and responsively exert desired forces on the snowboard or skis using the strength and leverage from the user's leg. If the interface between the boot and the user's ankle and lower leg is too loose or soft, it is more difficult for the user to achieve a high level of control, particularly in competitive settings where high performance is a priority. The use of an EVA foam for the upper portion of the liner-that is the portion of the liner that wraps about the lower leg of the user-reduces the responsiveness of the fit between the user and the boot.

[0006] There remains a need, therefore, for a durable boot liner that provides sufficient support about the ankle of the user and a tight fit between the liner and the boot, while also providing a comfortable fit for the user.

SUMMARY OF THE INVENTION

[0007] A novel hybrid boot liner is disclosed that provides an improved coupling between the boot liner and the boot, while also providing good ankle support and a comfortable fit for the user.

[0008] The boot liner includes an upper having a semi-rigid top portion that is adapted to wrap about the lower leg of the user, proving a relatively sturdy fit thereto, and a flexible bottom portion that covers the user's foot and malleoli. A semi-rigid sole is attached to the lower edge of the bottom portion of the upper, the sole providing a sturdy and dimensionally stable base to the liner that is sized to closely fit within the boot.

[0009] In an embodiment of the invention, the sole includes a lasting board, which is stitchedly attached to the bottom portion of the upper, and an outsole that is affixed to the lasting board and wraps about a portion of the upper.

[0010] In an embodiment of the invention, the top portion and the bottom portion of the upper are fixedly attached to each other with stitches.

[0011] In an embodiment of the invention, the flexible bottom portion of the upper includes a resilient layer made from an ethylene vinyl acetate foam. The flexible bottom portion may also include a slick outer layer that facilitates insertion of the liner into the boot, and an absorbent inner lining.

[0012] In an embodiment of the invention, the semi-rigid top portion is a stitched construction including a protective outer lining affixed to a stiffening member, a cushioning inner layer, and a soft inner lining.

[0013] In an embodiment of the invention, the liner includes a vamp opening, and the liner further includes a strap assembly that extends across the vamp opening and is operative to tighten the liner about the ankle of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0015]FIG. 1 is a perspective view of a boot liner, in accordance with the present invention, shown being inserted into a snowboard boot;

[0016]FIG. 2 is a perspective view of a boot liner, shown in FIG. 1, in isolation;

[0017]FIG. 3 is a cross-sectional side view of the boot liner, shown in FIG. 2, with the strap assembly omitted for clarity; and

[0018]FIG. 4 is an exploded, disassembled side view of the boot liner, shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] An embodiment of a hybrid liner according to the present invention will now be described, with reference to the figures, wherein like numbers represent like parts. FIG. 1 shows a boot liner 100, exemplary of the present invention, and positioned to be inserted into a snowboard boot 90. The snowboard boot 90 shown is of conventional construction and includes a relatively rugged and weatherproof upper 92 that is attached to a relatively rigid sole 94. Although the liner of the present invention is disclosed with reference to a conventional snowboard boot for illustrative purposes, the invention is not intended to be limited to such boots, and it will be appreciated that the present invention may also be used with other footwear. The boot liner 100 is sized and shaped to be inserted fully into the boot 90, such that the outer surface of the boot liner 100 conforms relatively closely to the inner surface of the snowboard boot 90. As discussed in more detail below, the liner 100 includes a semi-rigid sole 140 fixedly attached to a hybrid upper 101, the upper 101 including a top portion 110 that is adapted to wrap generally about the lower leg of a user, and a bottom portion 120 that generally covers the top of a user's foot. The upper 101 includes a vamp opening 102, and a tongue 104 that extends generally through the vamp opening 102. A strap and lace assembly 150 is also provided to secure the vamp opening 102 in a generally closed position.

[0020] The boot liner 100 will now be described in detail, with reference to FIGS. 2-4, wherein FIG. 2 shows a perspective view of the liner 100 (with the user's leg 88 shown in phantom); FIG. 3 shows a cross-sectional side view, taken generally through a longitudinal center plane of the boot liner 100; and FIG. 4 shows a disassembled exploded view of the boot liner 100. The boot liner 100 includes an upper 101 having a hybrid construction that is fixedly attached to a semi-rigid sole 140. The upper 101 includes a relatively stiff or semi-rigid top portion 110 that is shaped and sized to wrap about a lower portion of a user's leg 88. The front of the top portion 110 is split, defining an upper vamp opening 112. An upper tongue portion 114 extends generally through the upper vamp opening 112.

[0021] The upper 101 also includes a relatively flexible and pliable bottom portion 120 that is shaped to generally cover the upper surface and sides of a user's foot and malleoli (not shown). The front of the bottom portion 120 is split, defining a lower vamp opening 122. A lower tongue portion 124 extends upwardly generally from the toe 126 of the bottom portion 120 through the lower vamp opening 122. The lower tongue portion 124 may be formed integrally with the bottom portion 120 of the upper 101. The top portion 110 and the bottom portion 120 of the upper 101 are attached to each other—for example, by stitching 129—to form the upper 101, wherein the upper tongue portion 114 is also attached the lower tongue portion 124, to cooperatively form a tongue 104 that generally extends through the vamp opening 102 cooperatively formed by the upper vamp opening 112 and the lower vamp opening 122.

[0022] As seen most clearly in FIG. 3, the semi-rigid top portion 110 of the upper 101 in the disclosed embodiment is a stitched construction having a protective outer layer 111 bonded to a stiffener 113, a cushioning layer 115, and an inner lining 117. The stiffener 113 may be made from any suitable semi-rigid material, such as polyurethane. An example of an appropriate cushioning layer 115 material is a skived foam, although other cushioning materials may alternatively be used, as are known in the art. The inner lining 117 is preferably a soft, absorbent fabric. The upper tongue portion 114 is similar in construction to the top portion 110. Although the particular construction for the top portion 110 described is currently the preferred embodiment, it will be appreciated that other relatively rigid or semi-rigid constructions may alternatively be used, without departing from the spirit and scope of the present invention.

[0023] The bottom portion 120 of the upper 101, in contrast to the top portion 110, is relatively soft and pliable, preferably constructed with a flexible foam material and, most preferably, with a thermoformed ethylene vinyl acetate (“EVA”). EVA provides good cushioning, flexibility, and thermal properties, and is formable into a complex, three-dimensional shape to more accurately accommodate the complicated shape of a user's foot. It should be appreciated that the flexibility and formability of the lower portion is advantageous because, although the lower leg 88 of a user is relatively simple in geometry and inflexible, a user's foot is much more complicated in shape and is very flexible.

[0024] In the preferred embodiment the bottom portion 120 of the upper 101 includes a relatively slick outer layer 121 (such as a nylon fabric), a thick EVA layer 125, and a soft and absorbent inner lining 127. The inner lining 127 may be made from the same material as the inner lining 117 of the top portion 110 of the upper 101. The relatively slick outer layer 121 facilitates insertion and removal of the liner 100 from the boot 90 (see FIG. 1). The EVA layer 125 may preferably be thermoformed to a shape that comfortably accommodates the user's foot and lower ankle. The interface between the top portion 110 and bottom portion 120 of the upper 101, i.e., the stitching 129, is preferably disposed just above the malleoli of the user's ankle, such that these protuberances are comfortably wrapped with the relatively flexible bottom portion 120 of the upper 101.

[0025] Referring again to FIG. 2, the upper 101 may also include a securing device, such as a strap and lace assembly 150, comprising a strap plate 152 attached to the back side of the upper top portion 110 and a plurality of straps 154 that slidably engage the strap plate 150. In the disclosed embodiment, the straps 154 each define left and right loops or lace keepers 156 (only right lace keepers are shown) that accommodate a lace 158. The strap and lace assembly 150 provide a mechanism permitting the user to tighten the liner 100 and, in particular, the relatively rigid liner upper portion 110 about the user's lower leg. Although the preferred lace assembly has been described, it should be understood that other mechanisms for tightening the liner 100 about the foot and ankle of the user may alternatively be utilized, including, for example, hook and loop type straps, separate lace keepers attached directly at the vamp portion of the upper, and the like.

[0026] Referring now to FIG. 4, unlike other prior art liners, the sole 140 of the liner 100 of the disclosed embodiment includes a semi-rigid lasting board 160 that is attached to a lower edge 108 of the bottom portion 120 of the upper 101, preferably by stitching about the periphery of the lasting board 160. It will be appreciated that the lasting board 160 provides a secure and stable platform for the user's foot. A contoured sock liner or footbed 170 as are known in the art, which may be removable from the liner 100, is also provided. The footbed 150 is sized to fit closely within the inner wall of the upper 101 near the lower edge 108, and provides a comfortable and padded fit for the bottom of the user's foot.

[0027] The sole 140 also includes a rugged outsole 142, which is affixed to the undersurface of the lasting board 160, and wraps about the lower edge of the bottom portion 120 of the upper 101. The outsole 142 may be made of any suitable outsole material, as is well known in the art. The outsole 142 provides a nonskid undersurface with good wear properties, such that user can walk about in the liner 100, at least briefly, without damaging the liner 100. It will also be appreciated that the sole 140 provides a dimensionally stable lower surface that conforms closely to the boot 90, providing the user with a reliably responsive interface with the boot 90, and eliminates the packing out problems associated with some prior art boot liners, as discussed above. In the currently preferred embodiment, the outsole 142 is made from a second EVA foam material that is more rigid than the EVA foam used in the bottom portion 120 of the upper 101.

[0028] The liner construction disclosed herein permits the designer to include secondary cushioning elements normally associated with outer footwear. The secondary cushioning elements may be an air cell 144 disposed generally within the foam outsole 142. Other secondary cushioning elements include, for example, one or more sections of outsole utilizing a different EVA or other material having a lower durometer or hardness, or a gel insert.

[0029] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. 

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. A boot liner comprising: an upper having a semi-rigid top portion that is shaped to wrap around part of a user's lower leg and a non-rigid bottom portion, the non-rigid bottom portion being shaped to cover the user's foot and malleoli, the bottom portion having a lower edge; and a semi-rigid sole attached to the lower edge of the bottom portion of the upper.
 2. The boot liner of claim 1, wherein the top portion of the upper is attached to the bottom portion of the upper with stitches.
 3. The boot liner of claim 1, wherein the non-rigid bottom portion comprises a thermoformed ethylene vinyl acetate foam.
 4. The boot liner of claim 3, wherein the semi-rigid sole comprises a lasting board and an outsole fixedly attached to the lasting board.
 5. The boot liner of claim 4, wherein the outsole comprises a second ethylene vinyl acetate material that is more rigid than the ethylene vinyl acetate foam of the bottom portion of the upper.
 6. The boot liner of claim 4, wherein the semi-rigid top portion of the upper comprises a protective outer layer, a stiffener bonded to the protective outer layer, a cushioning layer, and an inner lining stitchedly attached to the protective outer layer.
 7. The boot liner of claim 4, wherein the lasting board is attached to the circumferential edge of the bottom portion of the upper with stitches.
 8. The boot liner of claim 4, wherein the outsole further comprises a secondary cushioning member disposed in a heel portion of the outsole.
 9. The boot liner of claim 8, wherein the secondary cushioning member is an air cell.
 10. The boot liner of claim 3, wherein the upper defines a vamp opening and further comprising a plurality of lace keepers attached to the semi-rigid top portion of the upper and a lace slidably disposed in the lace keepers.
 11. A boot liner removably insertable into a snowboard boot, the boot liner comprising: an upper having a flexible foot covering portion and a semi-rigid ankle support portion attached to an upper edge of the foot covering portion, the foot covering portion having a lower edge; and a sole having a semi-rigid lasting board attached to the lower edge of the foot covering portion of the upper, and a nonskid outsole affixed to the lasting board and the foot covering portion of the upper.
 12. The boot liner of claim 11, wherein the semi-rigid ankle support portion of the upper is attached to the flexible foot-covering portion of the upper with stitches.
 13. The boot liner of claim 11, wherein the flexible foot-covering portion comprises a thermoformed ethylene vinyl acetate foam.
 14. The boot liner of claim 13, wherein the outsole comprises a second ethylene vinyl acetate material that is more rigid than the ethylene vinyl acetate foam of the bottom portion of the upper.
 15. The boot liner of claim 13, wherein the semi-rigid ankle support portion of the upper comprises a protective outer layer, a stiffener bonded to the protective outer layer, a cushioning layer and an inner lining stitchedly attached to the protective outer layer.
 16. The boot liner of claim 13, wherein the lasting board is attached to the circumferential edge of the bottom portion of the upper with stitches.
 17. The boot liner of claim 11, wherein the outsole further comprises a secondary cushioning member disposed in a heel portion of the outsole.
 18. The boot liner of claim 17, wherein the secondary cushioning member is an air cell.
 19. The boot liner of claim 13, wherein the upper defines a vamp opening, and further comprising a plurality of lace keepers attached to the semi-rigid top portion of the upper and a lace slidably disposed in the lace keepers.
 20. A boot liner comprising: a hybrid upper assembly comprising a non-rigid foot portion having a longitudinal slit, and a semi-rigid ankle support portion fixedly attached to the foot portion, the leg portion having a generally vertical slit, wherein the longitudinal slit and the vertical slit cooperatively define a vamp opening in the hybrid upper assembly, the hybrid upper assembly further comprising an elongate tongue that is fixedly attached to the non-rigid foot portion and extends through the length of the vamp opening; and a semi-rigid sole attached to the upper assembly having a nonskid outsole.
 21. The boot liner of claim 20, wherein the non-rigid foot portion comprises a thermoformed ethylene vinyl acetate foam.
 22. The boot liner of claim 21, wherein the semi-rigid ankle support portion of the upper comprises a stitched construction having a protective outer layer, a semi-rigid stiffener, a cushioning layer, and an inner lining.
 23. The boot liner of claim 21, wherein the outsole comprises a second ethylene vinyl acetate material that is more rigid than the ethylene vinyl acetate foam of the bottom portion of the upper.
 24. The boot liner of claim 21, wherein the sole further comprises a lasting board that is fixedly attached to the non-rigid foot portion of the upper.
 25. The boot liner of claim 24, wherein the sole further comprises a secondary cushioning member disposed in a heel portion of the outsole.
 26. The boot liner of claim 25, wherein the secondary cushioning member is an air cell. 